Crankshafts or the like

ABSTRACT

A crank unit comprising a pair of mutual or co-acting disc-like members, each member having a central hole for a mounting shaft, the members being spaced apart by a circular flange affixed to one or both members, and the flange being arranged eccentrically about the central hole axis.

United States Patent 1 [111 3,747,433

Crowe July 24, 1973 [54] CRANKSHAFTS OR THE LIKE 710,865 10 1902 Hollender 74 570 Inventor: Charles Vivian Crowe, 161 738,252 9/1903 Stubbs 74/570 Cambridge Rd., Hamilton, New

Zealand Primary Examiner-Charles J. Myhre Assistant Examiner-F. D. Shoemaker [22] Fled: 1971 AnorneyS. Delvalle Goldsmith. Lester Horitz et al.

[21] Appl. No.: 202,244

[57] ABSTRACT [52] US. Cl 74/598, 74/570, 74/597 [51] Int. Cl. Fl6c 3/10 A crank compnsmg of mutual or co'actmg 581 Field of Search "74/598 597 595 disc'fike members each membe having a 74/570, 57] R, 571 M, 568 R 567 571 L for a mounting shaft, the members being spaced apart by a circular flange affixed to one or both members,

[56] References Cited and the flange being arranged eccentrically about the 7 central hole axis. UNITED STATES PATENTS 352,995 -ll/l886 Kaiser 74/571 M X 8 Claims, 5 Drawing Figures g z. 13 2 16 l CRANKSHAFTS on THE LIKE This invention relates to improvements in crankshafts designed more particularly for engines.

A conventional crankshaft essentially consists of a main shaft carrying at least one crank for the attachment of a connecting rod. A typical crankshaft has a plurality of crankpins each being connected by side arms or webs to main bearings of the shaft. The throw of the crankpins and their angular relationship is dependent upon the type and design of the engine. This means that a complicated design of crankshaft subsists and results in costly production techniques such as dropforging.

The present invention is concerned with a novel form of crank unit being of a simple nature and easy to install for operation.

The present invention is further concerned with a novel form of crankshaft having such an arrangement of its parts that a simple construction and one capable of being set to suit design of a particular engine.

In one aspect the invention consists of a crank unit comprising a pair of mutual or co-acting disc-like members, each member having a central hole for a mounting shaft, the members being spaced apart by a circular flange affixed to one or both members, and the flange being arranged eccentrically about the central hole axis.

In a further aspect the invention consists of a crankshaft and at least one crank unit according to the previous aspect being mounted on a shaft passing through their central hole, whereby the flange provides an axis or a crank for the big end of a piston or cross-ahead connecting rod.

In further-describing the invention, reference will be made hereinafter to the accompanying drawings, in which:

FIG. 1 is a side view and FIG. 2 is an exploded side view of the crank unit,

FIG. 3 is a view taken on the line 3-3 in FIG. 2 and FIG. 4 is a view taken on the line 4-4 in FIG. 2,

FIG. 5 is a side view of a modified form of the unit.

In giving effect to the first aspect of the invention, as a preferred embodiment, the crank unit has its two members l0, 11 cast from a special quality steel to greatly simplify production. Each member 10 or 11 is generally formed out of a circular shape but with a por tion of its marginal peripheral portion 12 reduced to a smaller lobe section 13 having an offset centre which in effect is the throw of the crankshaft.

This peripheral shaped portion 12of each member provides for its main area to be disposed concentrically about a true centre of the member and thus provides to contribute a balancing mass about such true centre.

Concentric with this centre the member is formed with a boss 14 on its outer side, relative to the other member and its hole is bored through to take the shaft 15.

The central eccentric flange 16 is also formed integral with the disc or body of the member in the nature of a boss on its inner side. This flange 16 is only provided on the member 10 and has its circular periphery arranged to encompass the hole for the main shaft. This flange 16 has a width so as to space the two members 10, 11 a distance dependent upon the operative width of the big-end of the particular connecting rod for which the crankshaft is designed. And hereagain the design of the crankshaft can be varied with relation to its throw and the radius of its balance flanges and the relative arrangement of the latter with one another.

Each member 10 or 11 is preferably formed with a crescent-like cutout section 17 in its lobe section 13, the outer edge of the cutout section being concentric withoffset axis of the lobe section and the inner edge of the cutout section being concentric with the shaft hole axis through the respective member. The hole and the circular eccentric flange 16 are finished to fine accuracy, and the disc members may be machined to assist in giving perfection of balance.

In a lesser preferred embodiment, crank unit can be manufactured in one piece with its eccentric flange 16 connecting both of its disc-like members 10, 11 as shown in FIG. 5.

In the second aspect of the invention one member 10 of each crank unit is keyed or other wise locked on to the shaft 15. This shaft is the main shaft of a multicylinder internal combustion engine; and the shaft mounts a crank unit relative to each cylinder. A connecting' rod having an integral circular big-end shaped so that it may be freely fitted on the circular eccentric flange 16. The other member 1 1 is now keyed or otherwise locked on the shaft 15. To provide for angular adjustnient, the shaft is formed with a plurality of keyways and each member with a half keyway so that with a key the two members may be set in similar relationship or one out of balance with the other, i.e., the balance flanges out of register.

My novel form of crankshaft as just described has numerous advantages over present types of conventional crankshafts. For instance it includes a straight unbroken shaft to go through the engine regardless of the number of cylinders involved. It allows the crank to be set independently at any degree desiredon the shaft to match any timing sequence. It gives a much heavier and more robust unit for converting reciprocal movement to rotary motion without increasing the stroke of the piston. It allows a much greater distance of travel under power stroke with greater leverage and kinetic energy yet retaining the normal piston travel of an orthodox engine. It derives more thrust from combustion due to slower flame propagation owing to the piston being allowed to travel considerably slower than the peripheral speed of the bearing.

Again this crankshaft revolves within the specially designed connecting rod which is free of any bolts where the crank unit is a two member one to come loose or break and it does not cross centres as in the orthodox engine. This ensures smooth balanced operation. It is easy to manufacture and is thus a mass production type unit. The unit can be slipped on to the straight shaft and is conventionally locked in the desired position. By locking one or both members of the crank unit, the entire crankshaft assembly including the or each connecting rod, shaft, bearings and usual seals can be removed without undoing usual bolts or screws.

What is claimed is:

l. A crank unit for converting reciprocal to rotary motion comprising a pair of co-acting disc members, each member having a central hole for a mounting shaft, the members being spaced apart by a circular flange affixed to at least one said member, formed integrally with one said member as a boss of the inner side thereof and arranged eccentrically about the central hole.

centric with the true centre the member has a boss on v its outer side, relative to the other member, and its hole passes through such boss to accommodate a said shaft.

5. A crank unit as claimed in claim 1 wherein the pe- 4. riphery of the flange is of a diameter to encompass the hole for the shaft.

6. A crank unit as claimed in claim 1 wherein each member has a crescent shaped cutout extending through its lobe section.

7. A crank unit as claimed in claim 8 wherein the cutout has an outer edge concentric with the offset centre of the lobe section and an inner edge concentric with the central hole.

8. A crankshaft including at least one crank unit according to claim I mounted on a shaft passing through its central hole, the flange being a crank pin for the big end of a piston or cross-head connecting rod.

i i l I 

1. A crank unit for converting reciprocal to rotary motion comprising a pair of co-acting disc members, each member having a central hole for a mounting shaft, the members being spaced apart by a circular flange affixed to at least one said member, formed integrally with one said member as a boss of the inner side thereof and arranged eccentrically about the central hole.
 2. A crank unit as claimed in claim 1 wherein each member has a portion of its marginal peripheral portion reduced to form a lobe section having an offset centre corresponding to the throw of an associated crankshaft.
 3. A crank unit as claimed in claim 2 wherein the peripheral shaped portion of each member has an area disposed concentrically about a true centre of the member thereby to contribute a balancing mass about such true centre.
 4. A crank unit as claimed in claim 3, wherein concentric with the true centre the member has a boss on its outer side, relativE to the other member, and its hole passes through such boss to accommodate a said shaft.
 5. A crank unit as claimed in claim 1 wherein the periphery of the flange is of a diameter to encompass the hole for the shaft.
 6. A crank unit as claimed in claim 1 wherein each member has a crescent shaped cutout extending through its lobe section.
 7. A crank unit as claimed in claim 8 wherein the cutout has an outer edge concentric with the offset centre of the lobe section and an inner edge concentric with the central hole.
 8. A crankshaft including at least one crank unit according to claim 1 mounted on a shaft passing through its central hole, the flange being a crank pin for the big end of a piston or cross-head connecting rod. 